20 . 06 . 2018
Non-Celiac Gluten Sensitivity
The term “Non-Celiac Gluten Sensitivity” was introduced in 1978 but has recently gained more popularity. Basically, this pathology describes the appearance of symptoms triggered by the exposure to gluten (protein found in wheat, barley and rye). Symptoms manifest in less than 24 hours and are predominantly gastrointestinal (bloating, pain, diarrhea), but can also be extra-intestinal (lack of wellbeing, fatigue, headaches, etc.). The affected patients do not fulfill the diagnostic criteria for celiac disease, where there is actual mucosal destruction triggered by the immune response to gluten.
The estimated prevalence of NCGS varies from 0.6% to 10.6%, according to different studies. This wide range is due to the absence of specific diagnosis criteria for NCGS. Currently, the diagnosis is made when there is improvement of symptoms following strict gluten elimination from the diet.
Recent studies have demonstrated that the problem behind this dietary intolerance might not be gluten, exclusively. Actually, some experts defend that the term “Non-Celiac Wheat Sensitivity” is more correct.
The mechanisms potentially involved in the pathogenesis of this intolerance may be separated in the following categories:
- Non IgE mediated wheat allergy – cases where wheat ingestion directly stimulates the intestinal mucosa immune cells (lymphocytes, eosinophils, basophils) directly. This diagnosis is supported by the presence of serum anti-gliadin antibodies and/or the detection of eosinophils in the intestinal mucosa biopsies.
- Amylase/trypsin inhibitors – family of enzyme inhibitors that serve as protective proteins for wheat and other cereals. These agents may activate the intestinal immune system.
- Wheat germ agglutinin – these are lectins, which are substances that can directly bind to the glycoproteins on cell membranes. This binding induces the release of inflammatory cytokines leading to mucosal damage.
- FODMAPs (“Fermentable Oligo-, Di-, Mono-saccharides And Polyols”). These are carbohydrates that are resistant to digestion in the human small intestine, and can be fermented in the colon by the commensal bacteria. Wheat contains fructans, which are FODMAPs, and can therefore cause gastrointestinal symptoms.
We conclude that wheat, and other cereals, can affect our health in different ways. For people who suspect they may be intolerant, the most effective way to determine it is to strictly avoid wheat (include rye and barley too, since they also contain gluten) for 4-8 weeks and then reintroduce it, while attentively monitoring symptoms. If the gastrointestinal symptoms persist, the low FODMAP diet can be used as it has a success rate in ameliorating IBS (Irritable Bowel Syndrome) of about 70%.
Catassi, C et al.
“The Overlapping Area of Non-Celiac Gluten Sensitivity (NCGS) and Wheat-Sensitive Irritable Bowel Syndrome (IBS): An Update”
Nutrients 9, 1268 (2017)